THE OCEAN-BOTTOM SEISMIC CABLE SYSTEM BASED ON LOW-NOISE HIGH-SENSITIVE MOLECULAR-ELECTRONIC TRANSFER SENSORS.

The purpose of this work is to develop new solutions in seismic acquisition technique used in marine conditions to acquire seismic data for hydrocarbon search technologies at the sea bottom and in the transit zones. The ocean-bottom seismic cable system based on molecular-electronic sensors is a cable telemetry system consisting of units connected by cables that transmit the digitized signal to the receiving point on the vessel. Each unit is an assembly of a vertical molecular-electronic geophone, a molecular-electronic hydrophone, an analog-to-digital signal converter and an Ethernet switch. The seismic and acoustic signal conversion in molecular-electronic sensors is based on the principles of ion transfer that provides high sensitivity and low-noise level as well as high dynamic range. The operation frequency band is 1–300 Hz, which is wider than that of the majority of seismic nodes based on using standard (10 Hz) geophones and hydrophones. The technique of summing vertical geophone and hydrophone data to attenuate strong spectral notches caused by receiver ghost reverberation (receiver-side multiples) is generally accepted by the industry while using seabed seismic receivers deliver the optimum measurement of subsurface reflectivity. The solution allows to combine the cost effectiveness of seismic streamers with the data quality and freedom of ocean bottom nodes. The first marine tests showed good coverage of the seismic survey data compared to the ARAM ARIES II recording system. [ABSTRACT FROM AUTHOR]